公开(公告)号：EP1214562A1

公开(公告)日：2002-06-19

申请号：EP00960093.3

申请日：2000-09-13

Applicant: THERMA-WAVE INC.

Inventor： WEI, Lanhua ,  CHU, Hanyou ,  OPSAL, Jon

IPC: G01B11/06

CPC classification number: G01N21/211 ,  G01B11/065 ,  G01N21/9501 ,  H01L22/12

Abstract: This invention relates to ellipsometry and reflectometry optical metrology tools that are used to evaluate semiconductor wafers, and is directed to reducing errors associated with material surrounding a desired measurement area or pad. One aspect the present invention utilizes a technique where a series of measurements are made separated by a small stage jog as the optical spot is scanned over the measurement pad. Provided the surrounding material is the same on both sides of the pad, one finds that the data invariably has either a cup or inverted 'U' shape or an inverted cup or 'U' shape when viewed as a function of position. The minimum or maximum of the curve is then used to identify the center of the pad. In another aspect of the present invention, data collected at the center of the pad is treated as being created by a superposition of light coming from the pad material itself and light coming from the surrounding material.

公开(公告)号：EP1410110B1

公开(公告)日：2010-05-12

申请号：EP02746544.2

申请日：2002-06-17

Applicant: Therma-Wave, INC.

Inventor： OPSAL, Jon ,  CHU, Hanyou

IPC: G03F7/20

CPC classification number: G03F7/70616 ,  G01B11/24 ,  G01N21/211 ,  G03F7/705 ,  G03F7/70625

公开(公告)号：EP0991931A1

公开(公告)日：2000-04-12

申请号：EP98926446.0

申请日：1998-06-08

Applicant: THERMA-WAVE INC.

Inventor： OPSAL, Jon ,  CHEN, Li

IPC: G01N21/17

CPC classification number: G01N21/211 ,  G01N21/1717

Abstract: An apparatus for characterizing multilayer samples is disclosed. An intensity modulated pump beam is focused onto the sample surface to periodically excite the sample. A probe beam is focused onto the sample surface within the periodically excited area. The power of the reflected probe beam is measured by a photodetector. The output of the photodetector is filtered and processed to derive the modulated optical reflectivity of the sample. Measurements are taken at a plurality of pump beam modulation frequencies. In addition, measurements are taken as the lateral separation between the pump and probe beam spots on the sample surface is varied. The measurements at multiple modulation frequencies and at different lateral beam spot spacings are used to help characterize complex multilayer samples. In the preferred embodiment, a spectrometer is also included to provide additional data for characterizing the sample.

公开(公告)号：EP0914600B1

公开(公告)日：2002-10-09

申请号：EP97935177.2

申请日：1997-07-22

Applicant: THERMA-WAVE INC.

Inventor： ASPNES, David, E. ,  OPSAL, Jon

IPC: G01N21/21 ,  G01J4/04

CPC classification number: G01J3/02 ,  G01J3/0229 ,  G01J3/0232 ,  G01N21/211 ,  G01N2021/213

公开(公告)号：EP1203200A1

公开(公告)日：2002-05-08

申请号：EP00952376.2

申请日：2000-08-02

Applicant: THERMA-WAVE INC.

Inventor： ROSENCWAIG, Allan ,  OPSAL, Jon

IPC: G01B15/02 ,  G01B15/08 ,  G01N23/201 ,  H01L21/66

CPC classification number: G01B15/08 ,  G01B15/02 ,  H01L22/12 ,  H01L2924/0002 ,  H01L2924/00

Abstract: The teachings of the subject invention lead to a new application of the XRR and RXRR systems. In particular, it has been recognized for the first time that such systems can be used to measure thickness of a variety of thin films (both dielectric, opaque and metal films) on patterned wafers where the feature size is smaller than the measurement spot. Broadly speaking, one aspect of the invention is the recognition that XRR and RXRR systems can be used not only on test wafers but on patterned wafers as well. The approach of the present invention to measuring the film thicknesses of patterned semiconductor wafers using XRR relies on the recognition that the measured X-ray reflection curve can be attributed primarily to the thicknesses of the layers rather than the structure of the pattern.

公开(公告)号：EP0898703A1

公开(公告)日：1999-03-03

申请号：EP97926548.0

申请日：1997-04-30

Applicant: THERMA-WAVE INC.

Inventor： OPSAL, Jon ,  SIDOROWICH, John, J.

IPC: G01B11 ,  G01N21 ,  H01L21

CPC classification number: G01N21/8422

Abstract: An optical inspection device generates a plurality of measured optical data from inspection of a thin film stack. A processor evolves models of theoretical data, which are compared to the measured data, and a 'best fit' solution is provided as the result. Each model of theoretical data is represented by an underlying 'genotype' which is an ordered list of 'genes'. Each gene corresponds to a selected thin film parameter of interest. Many such individual genotypes are created thereby forming a 'population' of genotypes, which are evolved through the use of a genetic algorithm. Each genotype has a fitness associated therewith based on how much the theoretical data derived therefrom differs from the measured data. Individual genotypes are selected based on fitness, then a genetic operation is performed on the selected genotypes to produce new genotypes. Multiple generations of genotypes are evolved until an acceptable solution is obtained.

公开(公告)号：EP0787286A1

公开(公告)日：1997-08-06

申请号：EP95935196.0

申请日：1995-09-27

Applicant: THERMA-WAVE INC.

Inventor： FANTON, Jeffrey, T. ,  OPSAL, Jon

IPC: G01N21

CPC classification number: G01N21/211

Abstract: An optical inspection apparatus is disclosed for generating an ellipsometric output signal at a plurality of wavelengths, each signal being representative of an integration of measurements at a plurality of angles of incidence. A polarized, broad band light beam is focused through a lens onto a sample in a manner to create a spread of angles of incidence. The reflected beam is passed through a quarter-wave plate and a polarizer which creates interference effects between the two polarizations states in the beam. The beam is then passed through a filter which transmits two opposed radial quadrants of the beam and blocks light striking the remaining two quadrants. The beam is then focused and angularly dispersed as function of wavelength. Each element of a one-dimensional photodetector array generates an output signal associated with a specific wavelength and represents an integration of the phase-sensitive ellipsometric parameter (δ) at a plurality of angles of incidence. A second, independent measurement is taken in order to isolate the signal of interest. In one embodiment, the azimuthal angle of the filter is rotated by ninety degrees. The output signals from the second measurement are subtracted from the corresponding output signals from the first measurement to obtain the phase-sensitive ellipsometric information at a plurality of wavelengths. The ellipsometric information is used to analyze the sample.

公开(公告)号：EP1410110A2

公开(公告)日：2004-04-21

申请号：EP02746544.2

申请日：2002-06-17

Applicant: Therma-Wave, INC.

Inventor： OPSAL, Jon ,  CHU, Hanyou

IPC: G03F7/20

CPC classification number: G03F7/70616 ,  G01B11/24 ,  G01N21/211 ,  G03F7/705 ,  G03F7/70625

Abstract: A system for characterizing periodic structures formed on a sample on a real time basis is disclosed. Aspectroscopic measurement module is provided which generates output signals as a function of wavelength. The output signals are supplied to a processor for evavuation. The processor creates an initial theoretical model having a rectangular structure. The processor than calculates the theoretical optical response of that sample to broad band radiation. The calculated optical response is compared to normalized measured values at each of a plurality of wavelengths. Based on the comparison, the model configuration is modified to be closer to the actual measured structure. The processor recalculates the optical response of the modified model and compares the result to the normalized data. This process is repeated in an iterative manner until a best fit rectangular shape is achieved. Thereafter, the complexity of the model is iteratively increased, by dividing the model into layers each having an associated width and height. The model is fit to the data in an iterative manner until a best fit model is obtained which is similar in structure to the periodic structure. In the preferred embodiment, the processor consists of a plurality of parallel co-processors. The steps of calculating the optical response of the model is distributed to the processors as a function of wavelength so these calculations can be performed in parallel. An alternate embodiment using multiple angle of incidence measurements is also disclosed.

公开(公告)号：EP0898703B1

公开(公告)日：2002-07-03

申请号：EP97926548.5

申请日：1997-04-30

Applicant: THERMA-WAVE INC.

Inventor： OPSAL, Jon ,  SIDOROWICH, John, J.

IPC: G01N21/84 ,  G01B11/06

CPC classification number: G01N21/8422

公开(公告)号：EP1012571A1

公开(公告)日：2000-06-28

申请号：EP98926302.5

申请日：1998-06-05

Applicant: THERMA-WAVE INC.

Inventor： ROSENCWAIG, Allan ,  OPSAL, Jon ,  ASPNES, David, E. ,  FANTON, Jeffrey, T.

IPC: G01N21/21 ,  G01B11/06

CPC classification number: G01B11/0641

Abstract: An optical measurement system is disclosed for evaluating samples with multi-layer thin film stacks. The optical measurement system includes a reference ellipsometer and one or more non-contact optical measurement devices. The reference ellipsometer is used to calibrate the other optical measurement devices. Once calibration is completed, the system can be used to analyse multi-layer thin film stacks. In particular, the reference ellipsometer provides a measurement which can be used to determine the total optical thickness of the stack. Using that information coupled with the measurements made by the other optical measurement devices, more accurate information about individual layers can be obtained.